function! LightlineAleWarning()
let counts = ale#statusline#Count(bufnr(''))
let n_warnings = counts.style_warning + counts.warning + counts.info
return counts.total == 0 || n_warnings == 0
\ ? ''
\ : printf('%d ◆', n_warnings)
endfunction
Try (snipe-f-w) on the same line as ◆, before ◆.